Thread: Bad water pump?
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Old 11-20-2012, 05:52 PM
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invariant invariant is offline
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Location: San Diego, CA
Join Date: Jun 2007
Posts: 653
Mein Auto: 2008 335i
Originally Posted by maggasp View Post
Call me a luddite, but it's irritating that something like a water pump needs to be electronic. Then it fails without warning, (and there's no temp gauge to monitor the system) and costs 4x as much as it should. Why, all to save a couple MPG?
Electric water pump is actually a good idea, as it allows variable coolant flow (low for faster warm-up and low emissions and high when driving aggressively).

It also makes possible to circulate coolant after engine shutdown to cool down turbochargers in 335.

Bleeding cooling system after replacing coolant is also easier and is done without starting the engine.

But yes, it is expensive compared to belt driven pumps...
2008 E90 335i 6MT + SSK + CDV-delete / ZSP / aluminum / black leather / Conti DW + compact spare / integrated portable nav plus
2005 E83 X3 Auto
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